Nature's Nightlights: 5 Bioluminescent Organisms

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Some animals have the unique capacity to be bioluminescent. In fact, experts think that up to 76% of marine life has this unique property.

Bioluminescence Explained

Bioluminescence refers to the phenomenon wherein a living organism produces and emits light. This emitted light is produced by the release of energy from chemical reactions that take place within the organism. This chemical reaction involves both oxygen and the molecule luciferin.

As for glowing sharks and corals, theirs is not a case of bioluminescence. Bioluminescence is a chemical process. In contrast, fluorescence results from creatures that reflect striking back light.

Let's take a look at some of the world's enigmatic, bioluminescent organisms.

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Jellyfish

Over half of all species of jellyfish produce a certain kind of bioluminescence. This largely serves the purpose of deterring predators. There is even one species that releases lambent mucus in order to confuse possible executioners further.

One specific jellyfish species, Aequorea victoria, makes a green glow around its bell's rim. It does so by passing its initial blue light through the compound GFP (green fluorescent protein).

Interestingly, this protein's gene encoding was lab-synthesized. It is now artificially inserted into other species' DNA sequences. This is so that scientists may easily identify some areas in their bodies.

Anglerfish

Deep-sea anglerfish use glowing baubles that dangle from rods at the front of their mouths. They use this feature to tempt their prey.

Other fish end up attracted to and intrigued by the fishy lanterns. When they get near, the beast ends up inhaling them at the other end.

Squids

There are also several squid species that emit light that serves different purposes. There are deep-sea squid that release glowing ink or mucus in order to lead their predators into confusion.

There are also others, such as the bobtail squid, that use their light to possess small cavities in their body's underside, which house bioluminescent bacteria. As it emerges from the sand during the night, its cavities' openings contract and expand as a response to the moonlight that penetrates the waves above it. This is so that the visibility of its silhouette dampens for predators below it.

Lanternfish

Lanternfish are abundant in the sea. Interestingly, each of the over 200 species is equipped with a unique pattern of photophores that generate light. This is used for mating and signaling.

Such photophores have lens-shaped and transparent scales that cover tissues that emit light. Such lenses aid in the amplification and focusing of the light.

Fireflies

Among these bioluminescent creatures, fireflies are considerably more familiar. Adult fireflies are bioluminescent organisms. They glow in order to attract potential mates.

While both male and female fireflies are capable of bioluminescence, the most flashing fireflies across North America are actually male. The light flash pattern sends a message to females nearby about their firefly species and their interest in mating.